1. Field of the Invention
The present invention relates to clutch fasteners and more
particularly to clutch fasteners incorporating helical spring retention mechanisms.
2. Description of Related Art
Clutch type securing devices are well known for gripping and securing posts, studs, or the like. Clutch type securing devices often serve to provide an enclosure for the sharp ends of jewelry pins, tie pins, etc. Such devices come in various forms. For example, a plurality of fingers may be provided to grip the stud or post. Other arrangements include a plurality of plate-like devices which act as spring clutches. A common problem associated with such securing devices is a loss of the frictional force necessary to retain the pin. In such instances, the securing portion may be lost, leaving the pin exposed to possibly harm an individual.
Various clutch type securing devices have been presented in the past to overcome the aforementioned disadvantages. For example, U.S. Pat. No. 2,934,123 issued on Apr. 26, 1960 to Brancato discloses a coil insert with an outer engaging locking coil. The device includes a small locking spring which is introduced into a bore parallel to the cavity into which the screw thread insert of large diameter is to be placed. The locking spring is wound left-handed if the insert is wound right-handed, and vice versa. The locking spring engages between convolution portions of the screw thread insert to displace the engaged portions.
U.S. Pat. No. 3,010,745 issued on Nov. 28, 1961 to Blomstrand et al. discloses a frictionally driven wire connector. The device is constructed so that no tangential handles or other positive abutting members need be relied upon. The device includes a stiff, resilient coil having a forwardly directed enlarged opening and a diminished portion rearwardly thereof. The wire connector coil includes substantially circular convolutions, the rearmost of which are adapted to expand under unwinding force and automatically provide an increasing gripping relation to the inner surface of a sleeve.
U.S. Pat. No. 3,316,795 issued on May 2, 1967 to Tann discloses a fastening device including helical spring-like element. A piece of wire-like material is formed into a spring-like element wherein the convolutions of the spring-like element increase in diameter from one end of the spring to the other. By positioning the spring-like element within a tapered threaded nut, or around a tapered threaded screw, and rotating and advancing the nut or screw relative to the spring-like element, the spring-like element can be made to contract or expand radially. The expansion of the spring-like element can be utilized to seize or lock a member positioned within the spring-like element in the case of a nut, and the contraction utilized to lock a member positioned about the spring-like element in the case of the tapered threaded screw.
U.S. Pat. No. 3,945,070 issued on Mar. 23, 1976 to Hauser discloses a method of creating a wire thread cast insert. A wire of given cross-sectional shape is formed into a helical configuration. The pitch of the helical turns is adjusted over a major length of the configuration to a given value greater than the desired final given thread pitch to be provided in the threaded opening of a body. An internal support in the form of a core is introduced into the helical configuration. Thereafter, the material involved, plastic or metal, is molded or cast around the helical configuration and support until it hardens into a solid body. The internal support is then removed to leave a threaded opening in the body.
U.S. Pat. No. 3,945,089 issued on Mar. 23, 1976 to Gagnon discloses a securing device which is usable for studs of buttons, emblems, earrings, insignia and the like. The device includes a first part having a cylindrical stud extending therefrom. A second part is provided into which the stud may pass. The second part also includes a resilient clutch that grips a substantial length of the cylindrical stud.
U.S. Pat. No. 4,292,715 issued on Oct. 6, 1981 to Huddon discloses a clutch device for holding together two articles of jewelry such as earrings, pins, necklaces, etc. The clutch includes a tubular housing closed at both ends except for a small central opening in the center of each end. A coil spring is mounted in the housing with each of its ends turned inwardly toward the axis of the spring so that a sharp edge at the end presents itself to a pin entering the openings. The sharp edge grips the pin and holds it against removal. The second part of the clutch is a pin, having a diameter slightly less than the internal diameter of the spring, which may be attached to the article of jewelry. With the housing in one part and the pin in the other, two jewelry portions can be joined by a frictional gripping action.
U.K. Patent Application No. 2,032,251 published on May 8, 1980 discloses a point protector for tie pins and like articles of jewelry. The device includes a body constructed of resilient plastic materials. The body includes two end pieces which are contained in a metal casing. The metal casing is initially a tube which is counter-drilled at each end to provide locations for the end pieces. The body, one end piece, and the casing have bores to receive the point to be shielded.
Soviet Union Patent No. 759,758 issued in August 1980 discloses a detachable clamp joint with spiral insert having conical surfaces to join items for reliability. The device consists of an outer item containing a hole therein, an inner item having a tip, and an intermediate spiral insert which is made from a harder material and fits between the tip and the inner surface of the hole.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.